Who is Anna Halsey from Trouble Is My Business and what is their importance?

Anna Halsey is approximately two hundred and forty pounds. She is a middle-aged woman who has eyes that are as black as buttons and a soft, ruddy complexion. Anna is a detective, but makes her living in a way that doesn't get her hands dirty. When more is required from her, she farms out the work she requires to those more suited to field work. She smokes cigarettes in a long, black holder.